Gas heating device for a vapor deposition system

ABSTRACT

A method and system for depositing a thin film on a substrate using a vapor deposition process is described. The processing system comprises a gas heating device for heating one or more constituents of a film forming composition. The gas heating device comprises one or more resistive heating elements configured to receive an electrical current from one or more power sources. Additionally, the gas heating device comprises a mounting structure configured to support the one or more resistive heating elements. Furthermore, the gas heating device comprises one or more static mounting devices coupled to the mounting structure and configured to fixedly couple the one or more resistive heating elements to the mounting structure, and one or more dynamic mounting devices coupled to the mounting structure and configured to automatically compensate for changes in a length of each of the one or more resistive heating elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to pending U.S. patent application Ser. No.11/693,067, entitled “VAPOR DEPOSITION SYSTEM AND METHOD OF OPERATING”,filed on Mar. 29, 2007. The entire content of this application is hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a method and system for thin filmdeposition, and more particularly to a method and system for depositinga thin film using a vapor deposition process.

2. Description of Related Art

During material processing, such as semiconductor device manufacturingfor production of integrated circuits (ICs), vapor deposition is acommon technique to form thin films, as well as to form conformal thinfilms over and within complex topography, on a substrate. Vapordeposition processes can include chemical vapor deposition (CVD) andplasma enhanced CVD (PECVD). For example, in semiconductormanufacturing, such vapor deposition processes may be used for gatedielectric film formation in front-end-of-line (FEOL) operations, andlow dielectric constant (low-k) or ultra-low-k, porous or non-porous,dielectric film formation and barrier/seed layer formation formetallization in back-end-of-line (BEOL) operations, as well ascapacitor dielectric film formation in DRAM production.

In a CVD process, a continuous stream of film precursor vapor isintroduced to a process chamber containing a substrate, wherein thecomposition of the film precursor has the principal atomic or molecularspecies found in the film to be formed on the substrate. During thiscontinuous process, the precursor vapor is chemisorbed on the surface ofthe substrate while it thermally decomposes and reacts with or withoutthe presence of an additional gaseous component that assists thereduction of the chemisorbed material, thus, leaving behind the desiredfilm.

In a PECVD process, the CVD process further includes plasma that isutilized to alter or enhance the film deposition mechanism. Forinstance, plasma excitation can allow film-forming reactions to proceedat temperatures that are significantly lower than those typicallyrequired to produce a similar film by thermally excited CVD. Inaddition, plasma excitation may activate film-forming chemical reactionsthat are not energetically or kinetically favored in thermal CVD.

Other CVD techniques include hot-filament CVD (otherwise known ashot-wire CVD or pyrolytic CVD). In hot-filament CVD, a film precursor isthermally decomposed by a resistively heated filament, and the resultingfragmented molecules adsorb and react on the surface of the substrate toleave the desired film. Unlike PECVD, hot-filament CVD does not requireformation of plasma.

SUMMARY OF THE INVENTION

The invention relates to a system for depositing a thin film usingchemical vapor deposition (CVD).

The invention further relates to a method and system for depositing athin film using pyrolytic CVD, whereby a gas heating device comprisingone or more resistive film heating elements is utilized to pyrolize afilm forming composition.

According to one embodiment, a gas heating device is described. The gasheating device may be configured to heat one or more constituents of afilm forming composition. The gas heating device comprises one or moreresistive heating elements configured to receive an electrical currentfrom one or more power sources. Additionally, the gas heating devicecomprises a mounting structure configured to support the one or moreresistive heating elements. Furthermore, the gas heating devicecomprises one or more static mounting devices coupled to the mountingstructure and configured to fixedly couple the one or more resistiveheating elements to the mounting structure, and one or more dynamicmounting devices coupled to the mounting structure and configured toautomatically compensate for changes in a length of each of the one ormore resistive heating elements. Further yet, the one or more dynamicmounting devices may substantially reduce slippage between the one ormore resistive heating elements and the one or more dynamic mountingdevices.

According to another embodiment, a processing system for depositing athin film on a substrate is described. The processing system comprises aprocess chamber having a pumping system configured to evacuate theprocess chamber, a substrate holder coupled to the process chamber andconfigured to support the substrate, and a gas distribution systemcoupled to the process chamber and configured to introduce a filmforming composition to a process space in the vicinity of a surface ofthe substrate. Further, the processing system comprises the gas heatingdevice described above coupled to an outlet of the gas distributionsystem.

According to another embodiment, a gas heating device configured to becoupled to a processing system for depositing a thin film on a substrateis described, comprising: a resistive heating element configured toreceive an electrical current from a power source; a mounting structureconfigured to support the resistive heating element; a static mountingdevice coupled to the mounting structure and configured to fixedlycouple the resistive heating element to the mounting structure; and adynamic mounting device coupled to the mounting structure and configuredto automatically compensate for changes in a length of the resistiveheating element, wherein the resistive heating element comprises a firstend fixedly coupled to the static mounting device, a second end fixedlycoupled to the static mounting device, a bend coupled to the dynamicmounting device and located between the first end and the second end, afirst straight section extending between the first end and the bend, anda second straight section extending between the second end and the bend,and wherein the first straight section and the second straight sectionare substantially the same length.

According to yet another embodiment, a method of depositing a thin filmon a substrate is described, the method comprising: coupling a gasheating device to a process chamber, the gas heating device comprisingone or more resistive heating elements and a mounting structureconfigure to support the one or more resistive elements; elevating atemperature of the one or more resistive heating elements; automaticallycompensating for a change in the length of the one or more resistiveheating elements while substantially reducing slippage between the oneor more resistive heating elements and the mounting structure; providinga substrate on a substrate holder in the process chamber of a depositionsystem; providing a film forming composition to a gas distributionsystem located above the substrate and opposing an upper surface of thesubstrate; pyrolizing one or more constituents of the film formingcomposition using the gas heating device; and exposing the substrate tothe film forming composition in the process chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 depicts a schematic view of a deposition system according to anembodiment;

FIG. 2 depicts a schematic view of a gas distribution system accordingto an embodiment;

FIG. 3 provides a top view of a gas heating device according to anembodiment;

FIG. 4A provides a top view of a heating element according to anembodiment;

FIG. 4B provides a side view of the heating element shown in FIG. 4A;

FIG. 5A provides a top view of a dynamic mounting device according to anembodiment;

FIG. 5B provides a side view of the dynamic mounting device shown inFIG. 5A;

FIG. 6 provides a top view of a heating element according to anotherembodiment;

FIG. 7 provides a top view of a heating element according to yet anotherembodiment; and

FIG. 8 illustrates a method of depositing a film on a substrateaccording to an embodiment.

DETAILED DESCRIPTION OF SEVERAL EMBODIMENTS

In the following description, in order to facilitate a thoroughunderstanding and for purposes of explanation and not limitation,specific details are set forth, such as a particular geometry of thedeposition system and descriptions of various components.

However, one skilled in the relevant art will recognize that the variousembodiments may be practiced without one or more of the specificdetails, or with other replacement and/or additional methods, materials,or components. In other instances, well-known structures, materials, oroperations are not shown or described in detail to avoid obscuringaspects of various embodiments of the invention. Similarly, for purposesof explanation, specific numbers, materials, and configurations are setforth in order to provide a thorough understanding of the invention.Nevertheless, the invention may be practiced without specific details.Furthermore, it is understood that the various embodiments shown in thefigures are illustrative representations and are not necessarily drawnto scale.

In the description and claims, the terms “coupled” and “connected,”along with their derivatives, are used. It should be understood thatthese terms are not intended as synonyms for each other. Rather, inparticular embodiments, “connected” may be used to indicate that two ormore elements are in direct physical or electrical contact with eachother while “coupled” may further mean that two or more elements are notin direct contact with each other, but yet still co-operate or interactwith each other.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure, material, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention, but do not denote that theyare present in every embodiment. Thus, the appearances of the phrases“in one embodiment” or “in an embodiment” in various places throughoutthis specification are not necessarily referring to the same embodimentof the invention. Furthermore, the particular features, structures,materials, or characteristics may be combined in any suitable manner inone or more embodiments. Various additional layers and/or structures maybe included and/or described features may be omitted in otherembodiments.

Referring now to the drawings, wherein like reference numerals designateidentical or corresponding parts throughout the several views, FIG. 1schematically illustrates a deposition system 1 for depositing a thinfilm, such as a conductive film, a non-conductive film, or asemi-conductive film. For example, the thin film can include adielectric film, such as a low dielectric constant (low-k) orultra-low-k dielectric film, or the thin film may include a sacrificiallayer for use in air gap dielectrics. Deposition system 1 can include achemical vapor deposition (CVD) system, whereby a film formingcomposition is thermally activated or decomposed in order to form a filmon a substrate. For example, the deposition system 1 comprises apyrolytic CVD system.

The deposition system 1 comprises a process chamber 10 having asubstrate holder 20 configured to support a substrate 25, upon which thethin film is formed. Furthermore, the substrate holder is configured tocontrol the temperature of the substrate at a temperature suitable forthe film forming reactions.

The process chamber 10 is coupled to a film forming composition deliverysystem 30 configured to introduce a film forming composition to theprocess chamber 10 through a gas distribution system 40. Furthermore, agas heating device 45 is coupled to the gas distribution system 40 andconfigured to chemically modify the film forming composition. The gasheating device 45 comprises one or more heating elements 55 disposed onan interior surface of the gas distribution system 40 or embedded withinthe gas distribution system 40 or both, and a power source 50 that iscoupled to the one or more heating elements 55 and that is configured todeliver electrical power to the one or more heating elements 55. Forexample, the one or more heating elements 55 can comprise one or moreresistive heating elements. When electrical current flows through andeffects heating of the one or more resistive heating elements, theinteraction of these heated elements with the film forming compositioncauses pyrolysis of one or more constituents of the film formingcomposition.

The process chamber 10 is further coupled to a vacuum pumping system 60through a duct 62, wherein the vacuum pumping system 60 is configured toevacuate the process chamber 10 and the gas distribution system 40 to apressure suitable for forming the thin film on the substrate 25 andsuitable for pyrolysis of the film forming composition.

The film forming composition delivery system 30 can include one or morematerial sources configured to introduce a film forming composition tothe gas distribution system 40. For example, the film formingcomposition may include one or more gases, or one or more vapors formedin one or more gases, or a mixture of two or more thereof. The filmforming composition delivery system 30 can include one or more gassources, or one or more vaporization sources, or a combination thereof.Herein vaporization refers to the transformation of a material (normallystored in a state other than a gaseous state) from a non-gaseous stateto a gaseous state. Therefore, the terms “vaporization,” “sublimation”and “evaporation” are used interchangeably herein to refer to thegeneral formation of a vapor (gas) from a solid or liquid precursor,regardless of whether the transformation is, for example, from solid toliquid to gas, solid to gas, or liquid to gas.

When the film forming composition is introduced to the gas distributionsystem 40, one or more constituents of the film forming composition aresubjected to pyrolysis by the gas heating device 45 described above. Thefilm forming composition can include film precursors that may or may notbe fragmented by pyrolysis in the gas distribution system 40. The filmprecursor or precursors may include the principal atomic or molecularspecies of the film desired to be produced on the substrate.Additionally, the film forming composition can include a reducing agentthat may or may not be fragmented by pyrolysis in the gas distributionsystem 40. The reducing agent or agents may assist with the reduction ofa film precursor on substrate 25. For instance, the reducing agent oragents may react with a part of or all of the film precursor onsubstrate 25. Additionally yet, the film forming composition can includea polymerizing agent (or cross-linker) that may or may not be fragmentedby pyrolysis in the gas distribution system 40. The polymerizing agentmay assist with the polymerization of a film precursor or fragmentedfilm precursor on substrate 25.

According to one embodiment, when forming a copolymer thin film onsubstrate 25, a film forming composition comprising two or more monomergases is introduced to the gas distribution system 40 and is exposed tothe gas heating device 45, i.e., the one or more heating elements 55,having a temperature sufficient to pyrolyze one or more of the monomersand produce a source of reactive species. These reactive species areintroduced to and distributed within process space 33 in the vicinity ofthe upper surface of substrate 25. Substrate 25 is maintained at atemperature lower than that of the gas heating device 45 in order tocondensate and induce polymerization of the chemically altered filmforming composition at the upper surface of substrate 25.

For example, when forming an organosilicon polymer, monomer gas(es) ofan organosilicon precursor is used. Additionally, for example, whenforming a fluorocarbon-organosilicon copolymer, monomer gases of afluorocarbon precursor and organosilicon precursor are used.

Further yet, the film forming composition can include an initiator thatmay or may not be fragmented by pyrolysis in the gas distribution system40. An initiator or fragmented initiator may assist with thefragmentation of a film precursor, or the polymerization of a filmprecursor. The use of an initiator can permit higher deposition rates atlower heat source temperatures. For instance, the one or more heatingelements can be used to fragment the initiator to produce radicalspecies of the initiator (i.e., a fragmented initiator) that arereactive with one or more of the remaining constituents in the filmforming composition. Furthermore, for instance, the fragmented initiatoror initiator radicals can catalyze the formation of radicals of the filmforming composition.

For example, when forming a fluorocarbon-organosilicon copolymer, theinitiator can be perfluorooctane sulfonyl fluoride (PFOSF) used in thepolymerization of a cyclic vinylmethylsiloxane, such as1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane (V₃D₃).

Additionally, for example, when forming a porous SiCOH-containing film,the film forming composition may comprise a structure-forming materialand a pore-generating material. The structure-forming material maycomprise diethoxymethylsilane (DEMS) and the pore-generating materialmay comprise alpha-terpinene (ATRP). The porous SiCOH-containing filmmay be used as a low dielectric constant (low-k) material.

Further, for example, when forming a cross-linked neopentyl methacrylateorganic glass, the film forming composition may comprise a monomer, across-linker, and an initiator. The monomer may comprisetrimethylsilylmethyl methacrylate (TMMA), propargyl methacrylate (PMA),cyclopentyl methacrylate (CPMA), neopentyl methacrylate (npMA), and poly(neopentyl methacrylate) (P(npMA)), and the cross-linker may compriseethylene glycol diacrylate (EGDA), ethylene glycol dimethacrylate(EGDMA), 1,3-propanediol diacrylate (PDDA), or 1,3-propanedioldimethacrylate (PDDMA), or any combination of two or more thereof.Additionally, the initiator may comprise a peroxide, a hydroperoxide, ora diazine. Additionally yet, the initiator may comprise a tert-butylperoxide (TBPO).

Further yet, for example, the polymer film may comprise P(npMA-co-EGDA)(poly(neopentyl methacrylate-co-ethylene glycol diacrylate)), and themonomer comprises npMA (neopentyl methacrylate) and the cross-linkercomprises EGDA (ethylene glycol diacrylate). The polymer film may beused as a sacrificial air gap material.

According to one embodiment, the film forming composition deliverysystem 30 can include a first material source 32 configured to introduceone or more film precursors to the gas distribution system 40, and asecond material source 34 configured to introduce a (chemical) initiatorto the gas distribution system 40. Furthermore, the film formingcomposition delivery system 30 can include additional gas sourcesconfigured to introduce an inert gas, a carrier gas or a dilution gas.For example, the inert gas, carrier gas or dilution gas can include anoble gas, i.e., He, Ne, Ar, Kr, Xe, or Rn.

Referring now to FIG. 2, a gas distribution system 200 is illustratedaccording to an embodiment. The gas distribution system 200 comprises ahousing 240 configured to be coupled to or within a process chamber of adeposition system (such as process chamber 10 of deposition system 1 inFIG. 1), and a gas distribution plate 241 configured to be coupled tothe housing 240, wherein the combination form a plenum 242. The gasdistribution system 200 may be thermally insulated from the processchamber, or it may not be thermally insulated from the process chamber.

The gas distribution system 200 is configured to receive a film formingcomposition into the plenum 242 from a film forming composition deliverysystem (not shown) and distribute the film forming composition in theprocess chamber. For example, the gas distribution system 200 can beconfigured to receive one or more constituents of a film formingcomposition 232 and an optional initiator 234 into plenum 242 from thefilm forming composition delivery system. The one or more constituentsof the film forming composition 232 and the optional initiator 234 maybe introduced to plenum 242 separately as shown, or they may beintroduced through the same opening.

The gas distribution plate 241 comprises a plurality of openings 244arranged to introduce and distribute the film forming composition fromplenum 242 to a process space 233 proximate a substrate (not shown) uponwhich a film is to be formed. For example, gas distribution plate 241comprises an outlet 246 configured to face the upper surface of asubstrate.

Furthermore, the gas distribution system 200 comprises a gas heatingdevice 250 having one or more heating elements 252 coupled to a powersource 254 and configured to receive an electrical current from thepower source 254. The one or more heating elements 252 are located atthe outlet 246 of the gas distribution system 200, such that they mayinteract with any constituent of the film forming composition, or all ofthe constituents of the film forming composition including the optionalinitiator.

For example, the one or more heating elements 252 can comprise one ormore resistive heating elements. Additionally, for example, the one ormore heating elements 252 may include a metal-containing ribbon.Furthermore, for example, the one or more heating elements 252 can becomposed of a resistive metal, a resistive metal alloy, a resistivemetal nitride, or a combination of two or more thereof.

When the power source 254 couples electrical power to the one or moreheating elements 252, the one or more heating elements 252 may beelevated to a temperature sufficient to pyrolize one or moreconstituents of the film forming composition. Power source 254 mayinclude a direct current (DC) power source, or it may include analternating current (AC) power source. Power source 254 may beconfigured to couple electrical power to the one or more heatingelements 252 through a direct electrical connection to the one or moreheating elements 252. Alternatively, power source 254 may be configuredto couple electrical power to the one or more heating elements 252through induction.

The one or more openings 244 formed in gas distribution plate 241 caninclude one or more orifices or one or more slots or a combinationthereof. The one or more openings 244 can include a plurality oforifices distributed on the gas distribution plate 241 in a rectilinearpattern. Alternatively, the one or more openings 244 can include aplurality of orifices distributed on the gas distribution plate 241 in acircular pattern (e.g., orifices are distributed in a radial directionor angular direction or both). When the one or more heating elements 252are located at the outlet 246 of the gas distribution system 200, eachheating element can be positioned such that the flow of film formingcomposition and/or the optional initiator exiting from the one or moreopenings 244 of gas distribution plate 241 pass by or over each heatingelement.

Additionally, the plurality of openings 244 can be distributed invarious density patterns on the gas distribution plate 241. For example,more openings can be formed near the center of the gas distributionplate 241 and less openings can be formed near the periphery of the gasdistribution plate 241. Alternatively, for example, more openings can beformed near the periphery of the gas distribution plate 241 and lessopenings can be formed near the center of the gas distribution plate241. Additionally yet, the size of the openings can vary on the gasdistribution plate 241. For example, larger openings can be formed nearthe center of the gas distribution plate 241 and smaller openings can beformed near the periphery of the gas distribution plate 241.Alternatively, for example, smaller openings can be formed near theperiphery of the gas distribution plate 241 and larger openings can beformed near the center of the gas distribution plate 241.

Referring still to FIG. 2, the gas distribution system 200 may comprisean optional intermediate gas distribution plate 260 coupled to housing240 such that the combination of housing 240, intermediate gasdistribution plate 260 and gas distribution plate 241 form anintermediate plenum 245 separate from plenum 242 and between theintermediate gas distribution plate 260 and the gas distribution plate241. The gas distribution system 200 is configured to receive a filmforming composition into the plenum 242 from a film forming compositiondelivery system (not shown) and distribute the film forming compositionthrough the intermediate plenum 245 to the process chamber.

The intermediate gas distribution plate 260 comprises a plurality ofopenings 262 arranged to distribute and introduce the film formingcomposition to the intermediate plenum 245. The plurality of openings262 can be shaped, arranged, distributed or sized as described above.

The gas distribution system 200 may further comprise an optional gasdistribution manifold 270 coupled to housing 240 such that thecombination of housing 240 and gas distribution manifold 270 form asecond intermediate plenum 243 separate from plenum 242 and between theintermediate gas distribution plate 260 and the gas distributionmanifold 270. The gas distribution system 200 is configured to receive afilm forming composition into the plenum 242 from a film formingcomposition delivery system (not shown) and distribute the film formingcomposition through the second intermediate plenum 243 and theintermediate plenum 245 to the process chamber. The intermediate gasdistribution plate 270 comprises a one or more conduits 272 configuredto distribute and introduce the film forming composition to the secondintermediate plenum 243 through an annular groove 274.

Referring now to FIG. 3, a top view of a gas heating device 300 ispresented according to an embodiment. The gas heating device 300 isconfigured to heat one or more constituents of a film formingcomposition. The gas heating device 300 comprises one or more heatsources 320, wherein each heat source 320 comprises a resistive heatingelement 330 configured to receive an electrical current from one or morepower sources. Additionally, the gas heating device 300 comprises amounting structure 310 configured to support the one or more resistiveheating elements 330. Furthermore, the one or more heat sources 320 maybe mounted between the mounting structure 310 and an auxiliary mountingstructure 312.

As shown in FIG. 3, the gas heating device 300 comprises one or morestatic mounting devices 326 coupled to the mounting structure 310 andconfigured to fixedly couple the one or more resistive heating elements330 to the mounting structure 310, and the gas heating device 300comprises one or more dynamic mounting devices 324 coupled to themounting structure 310 and configured to automatically compensate forchanges in a length of each of the one or more resistive heatingelements 330. Further yet, the one or more dynamic mounting devices 324may substantially reduce slippage between the one or more resistiveheating elements 330 and the one or more dynamic mounting devices 324.

The one or more resistive heating elements 330 may be electricallycoupled in series, as shown in FIG. 3, using electrical interconnects342, wherein electrical current is supplied to the serial connection ofone or more resistive heating elements 330 via, for example, connectionof a first terminal 340 to the power source and a second terminal 344 toelectrical ground for the power source. Alternatively, the one or moreresistive heating elements 330 may be electrically coupled in parallel.

Referring now to FIGS. 4A and 4B, a top view and a side view of heatsource 320, respectively, is presented according to an embodiment. Theresistive heating element 330 comprises a first end 334 fixedly coupledto one of the one or more static mounting devices 326, a second end 336fixedly coupled to one of the one or more static mounting devices 326, abend 333 coupled to one of the one or more dynamic mounting devices 324and located between the first end 334 and the second end 336, a firststraight section 332 extending between the first end 334 and the bend333, and a second straight section 331 extending between the second end336 and the bend 333. The first end 334 and the second end 336 may befixedly coupled to the same static mounting device or different staticmounting devices.

As illustrated in FIGS. 4A and 4B, the first straight section 332 andthe second straight section 331 may be substantially the same length.When the first straight section 332 and the second straight section 331are substantially the same length, the respective changes in length forthe first straight section 332 and the second straight section 331 dueto temperature variations are substantially the same. Alternatively, thefirst straight section 332 and the second straight section 331 may bedifferent lengths.

Also, as illustrated in FIGS. 4A and 4B, the bend 333 comprises a 180degree bend. Alternatively, the bend 333 comprises a bend ranging fromgreater than 0 degrees to less than 360 degrees.

The static mounting device 326 is fixedly coupled to the mountingstructure 310. The dynamic mounting device 324 is configured to adjustin a linear direction 325 parallel with the first straight section 332and the second straight section 331 in order to compensate for changesin the length of the first straight section 332 and the length of thesecond straight section 331. In this embodiment, the dynamic mountingdevice 324 can alleviate slack or sagging in the resistive heatingelement 330, and it may substantially reduce or minimize slippagebetween the resistive heating element 330 and the dynamic mountingdevice 324 (such slippage may cause particle generation and/orcontamination).

Referring now to FIGS. 5A and 5B, a top view and a side view of thedynamic mounting device 324, respectively, is presented according to anembodiment. The dynamic mounting device 324 comprises a static structure350 having a guide post 352, a helical spring 370 configured to slideover the guide post 352, and a dynamic structure 360 configured toslidably mate with the guide post 352 and compress the spring 370against the static structure 350 when loaded with one of the one or moreresistive heating elements 330. The restoring force of the helicalspring 370 may maintain the resistive heating element 330 under tensilestress and/or alleviate the resistive heating element 330 from slack orsagging.

The dynamic structure 360 comprises a shaped surface 362 configured tocontact band 333 of the resistive heating element 320. Additionally, thedynamic structure 360 comprises a bore 364 configured to slidably matewith the guide post 352. Moreover, the mounting structure 310 maycomprise a groove 314 configured to receive the base of the dynamicstructure 360 and further guide its motion.

Referring now to FIG. 6, a top view of a heat source 420 is presentedaccording to another embodiment. The heat source 420 comprises aresistive heating element 430 following a serpentine-like path thatweaves through a plurality of dynamic structures 424, 424′, 424″ coupledto a mounting structure 410 and configured to move in directions 425,425′, 425″, respectively. For example, the serpentine-like path maycomprise substantially straight sections interconnected by bends 433.One end of the serpentine-like path may be connected to a power source,while the opposing end of the serpentine-like path may be connected tothe electrical ground for the power source. In this embodiment, theplurality of dynamic mounting devices 424, 424′, 424″ can alleviateslack or sagging in the resistive heating element 430, and they maysubstantially reduce or minimize slippage between the resistive heatingelement 430 and the dynamic mounting devices 424 (such slippage maycause particle generation and/or contamination).

Referring now to FIG. 7, a top view of a heat source 520 is presentedaccording to another embodiment. The heat source 520 comprises one ormore resistive heating elements 530 coupled to a mounting structure 510.Each resistive heating element 530 comprises a first end fixedly coupledto a static mounting device 526, a second end fixedly coupled to adynamic mounting device 524, and a straight section extending betweenthe first end and the second end. The dynamic mounting device 524 isconfigured to move in direction 525. In this embodiment, the dynamicmounting device 524 can alleviate slack or sagging in the resistiveheating element 530, and it may substantially reduce or minimizeslippage between the resistive heating element 530 and the dynamicmounting device 524 (such slippage may cause particle generation and/orcontamination).

Referring again to FIG. 1, the power source 50 is configured to provideelectrical power to the one or more resistive film heating elements inthe gas distribution system 40. For example, the power source 50 can beconfigured to deliver either DC power or AC power. Additionally, forexample, the power source 50 can be configured to modulate the amplitudeof the power, or pulse the power. Furthermore, for example, the powersource 50 can be configured to perform at least one of setting,monitoring, adjusting or controlling a power, a voltage, or a current.

Referring still to FIG. 1, a temperature control system 22 can becoupled to the gas distribution system 40, the heat source 45, theprocess chamber 10 and/or the substrate holder 20, and configured tocontrol the temperature of one or more of these components. Thetemperature control system 22 can include a temperature measurementsystem configured to measure the temperature of the gas distributionsystem 40 at one or more locations, the temperature of the gas heatingdevice 45 at one or more locations, the temperature of the processchamber 10 at one or more locations and/or the temperature of thesubstrate holder 20 at one or more locations. The measurements oftemperature can be used to adjust or control the temperature at one ormore locations in deposition system 1.

The temperature measuring device, utilized by the temperaturemeasurement system, can include an optical fiber thermometer, an opticalpyrometer, a band-edge temperature measurement system as described inpending U.S. patent application Ser. No. 10/168,544, filed on Jul. 2,2002, the contents of which are incorporated herein by reference intheir entirety, or a thermocouple such as a K-type thermocouple.Examples of optical thermometers include: an optical fiber thermometercommercially available from Advanced Energies, Inc., Model No. OR2000F;an optical fiber thermometer commercially available from LuxtronCorporation, Model No. M600; or an optical fiber thermometercommercially available from Takaoka Electric Mfg., Model No. FT-1420.

Alternatively, when measuring the temperature of one or more resistiveheating elements, the electrical characteristics of each resistiveheating element can be measured. For example, two or more of thevoltage, current or power coupled to the one or more resistive heatingelements can be monitored in order to measure the resistance of eachresistive heating element. The variations of the element resistance canarise due to variations in temperature of the element which affects theelement resistivity.

According to program instructions from the temperature control system 22or the controller 80 or both, the power source 50 can be configured tooperate the gas heating device 45, e.g., the one or more heatingelements, at a temperature ranging from approximately 100 degrees C. toapproximately 600 degrees C. For example, the temperature can range fromapproximately 200 degrees C. to approximately 550 degrees C. Thetemperature can be selected based upon the film forming composition and,more particularly, the temperature can be selected based upon aconstituent of the film forming composition.

Additionally, according to program instructions from the temperaturecontrol system 22 or the controller 80 or both, the temperature of thegas distribution system 40 can be set to a value approximately equal toor less than the temperature of the gas heating device 45, i.e., the oneor more heating elements. For example, the temperature can be a valueless than or equal to approximately 600 degrees C. Additionally, forexample, the temperature can be a value less than approximately 550degrees C. Further yet, for example, the temperature can range fromapproximately 80 degrees C. to approximately 550 degrees C. Thetemperature can be selected to be approximately equal to or less thanthe temperature of the one or more heating elements, and to besufficiently high to prevent condensation which may or may not causefilm formation on surfaces of the gas distribution system and reduce theaccumulation of residue.

Additionally yet, according to program instructions from the temperaturecontrol system 22 or the controller 80 or both, the temperature of theprocess chamber 10 can be set to a value less than the temperature ofthe heat source 45, i.e., the one or more heating elements. For example,the temperature can be a value less than approximately 200 degrees C.Additionally, for example, the temperature can be a value less thanapproximately 150 degrees C. Further yet, for example, the temperaturecan range from approximately 80 degrees C. to approximately 150 degreesC. However, the temperature may be the same or less than the temperatureof the gas distribution system 40. The temperature can be selected to beless than the temperature of the one or more resistive film heatingelements, and to be sufficiently high to prevent condensation which mayor may not cause film formation on surfaces of the process chamber andreduce the accumulation of residue.

Once film forming composition enters the process space 33, the filmforming composition adsorbs on the substrate surface, and film formingreactions proceed to produce a thin film on the substrate 25. Accordingto program instructions from the temperature control system 22 or thecontroller 80 or both, the substrate holder 20 is configured to set thetemperature of substrate 25 to a value less than the temperature of thegas heating device 45, the temperature of the gas distribution system40, and the process chamber 10. For example, the substrate temperaturecan range up to approximately 80 degrees C. Additionally, the substratetemperature can be approximately room temperature. For example, thesubstrate temperature can range up to approximately 25 degrees C.However, the temperature may be less than or greater than roomtemperature.

The substrate holder 20 comprises one or more temperature controlelements coupled to the temperature control system 22. The temperaturecontrol system 22 can include a substrate heating system, or a substratecooling system, or both. For example, substrate holder 20 can include asubstrate heating element or substrate cooling element (not shown)beneath the surface of the substrate holder 20. For instance, theheating system or cooling system can include a re-circulating fluid flowthat receives heat from substrate holder 20 and transfers heat to a heatexchanger system (not shown) when cooling, or transfers heat from theheat exchanger system to the substrate holder 20 when heating. Thecooling system or heating system may include heating/cooling elements,such as resistive heating elements, or thermo-electric heaters/coolerslocated within substrate holder 20. Additionally, the heating elementsor cooling elements or both can be arranged in more than one separatelycontrolled temperature zone. The substrate holder 20 may have twothermal zones, including an inner zone and an outer zone. Thetemperatures of the zones may be controlled by heating or cooling thesubstrate holder thermal zones separately.

Additionally, the substrate holder 20 comprises a substrate clampingsystem (e.g., electrical or mechanical clamping system) to clamp thesubstrate 25 to the upper surface of substrate holder 20. For example,substrate holder 20 may include an electrostatic chuck (ESC).

Furthermore, the substrate holder 20 can facilitate the delivery of heattransfer gas to the back-side of substrate 25 via a backside gas supplysystem to improve the gas-gap thermal conductance between substrate 25and substrate holder 20. Such a system can be utilized when temperaturecontrol of the substrate is required at elevated or reducedtemperatures. For example, the backside gas system can comprise atwo-zone gas distribution system, wherein the backside gas (e.g.,helium) pressure can be independently varied between the center and theedge of substrate 25.

Vacuum pumping system 60 can include a turbo-molecular vacuum pump (TMP)capable of a pumping speed up to approximately 5000 liters per second(and greater) and a gate valve for throttling the chamber pressure. Forexample, a 1000 to 3000 liter per second TMP can be employed. TMPs canbe used for low pressure processing, typically less than approximately 1Torr. For high pressure processing (i.e., greater than approximately 1Torr), a mechanical booster pump and dry roughing pump can be used.Furthermore, a device for monitoring chamber pressure (not shown) can becoupled to the process chamber 10. The pressure measuring device can be,for example, a Type 628B Baratron absolute capacitance manometercommercially available from MKS Instruments, Inc. (Andover, Mass.).

Referring still to FIG. 1, the deposition system 1 can further comprisea controller 80 that comprises a microprocessor, memory, and a digitalI/O port capable of generating control voltages sufficient tocommunicate and activate inputs to deposition system 1 as well asmonitor outputs from deposition system 1. Moreover, controller 80 can becoupled to and can exchange information with the process chamber 10, thesubstrate holder 20, the temperature control system 22, the film formingcomposition supply system 30, the gas distribution system 40, the gasheating device 45, and the vacuum pumping system 60, as well as thebackside gas delivery system (not shown), and/or the electrostaticclamping system (not shown). A program stored in the memory can beutilized to activate the inputs to the aforementioned components ofdeposition system 1 according to a process recipe in order to performthe method of depositing a thin film.

Controller 80 may be locally located relative to the deposition system1, or it may be remotely located relative to the deposition system 1 viaan internet or intranet. Thus, controller 80 can exchange data with thedeposition system 1 using at least one of a direct connection, anintranet, or the internet. Controller 80 may be coupled to an intranetat a customer site (i.e., a device maker, etc.), or coupled to anintranet at a vendor site (i.e., an equipment manufacturer).Furthermore, another computer (i.e., controller, server, etc.) canaccess controller 80 to exchange data via at least one of a directconnection, an intranet, or the internet.

The deposition system 1 can be periodically cleaned using an in-situcleaning system (not shown) coupled to, for example, the process chamber10 or the gas distribution system 40. Per a frequency determined by theoperator, the in-situ cleaning system can perform routine cleanings ofthe deposition system 1 in order to remove accumulated residue oninternal surfaces of deposition system 1. The in-situ cleaning systemcan, for example, comprise a radical generator configured to introducechemical radical capable of chemically reacting and removing suchresidue. Additionally, for example, the in-situ cleaning system can, forexample, include an ozone generator configured to introduce a partialpressure of ozone. For instance, the radical generator can include anupstream plasma source configured to generate oxygen or fluorine radicalfrom oxygen (O₂), nitrogen trifluoride (NF₃), O₃, XeF₂, ClF₃, or C₃F₈(or, more generally, C_(x)F_(y)), respectively. The radical generatorcan include an ASTRON® reactive gas generator, commercially availablefrom MKS Instruments, Inc., ASTeX® Products (90 Industrial Way,Wilmington, Mass. 01887).

Although the gas heating device has been described for use in adeposition system, the gas heating device may be used in any systemrequiring gas heating. Other systems in semiconductor manufacturing andintegrated circuit (IC) manufacturing may include etching systems,thermal processing systems, etc.

FIG. 8 illustrates a method of depositing a thin film on a substrateaccording to another embodiment. The method 800 includes, at 810,coupling a gas heating device to a process chamber for a depositionsystem, wherein the gas heating device comprises one or more resistiveheating elements and a mounting structure configure to support the oneor more resistive elements.

In 820, a temperature of the one or more resistive heating elements iselevated. For example, the temperature may be elevated by flowingelectrical current through the one or more resistive heating elements.

In 830, a change in the length of the one or more resistive heatingelements is automatically compensated by one or more dynamic mountingdevices coupled to the mounting structure. For example, the compensationfor the change in element length may be performed while substantiallyreducing slippage between the one or more resistive heating elements andthe dynamic mounting device.

In 840, a substrate is provided in the process chamber of the depositionsystem. For example, the deposition system can include the depositionsystem described above in FIG. 1. The substrate can, for example, be aSi substrate. A Si substrate can be of n- or p-type, depending on thetype of device being formed. The substrate can be of any size, forexample a 200 mm substrate, a 300 mm substrate, or an even largersubstrate. According to an embodiment of the invention, the substratecan be a patterned substrate containing one or more vias or trenches, orcombinations thereof.

In 850, a film forming composition is provided to a gas distributionsystem that is configured to introduce the film forming composition tothe process chamber above the substrate. For example, the gasdistribution system can be located above the substrate and opposing anupper surface of the substrate.

In 860, one or more constituents of the film forming composition aresubjected to pyrolysis using the gas heating device. The gas heatingdevice can be any one of the systems described in FIGS. 2 through 7above, or any combination thereof.

In 870, the substrate is exposed to the film forming composition tofacilitate the formation of the thin film. The temperature of thesubstrate can be set to a value less than the temperature of the one ormore heating elements, e.g. one or more resistive film heating elements.For example, the temperature of the substrate can be approximately roomtemperature.

Although only certain embodiments of this invention have been describedin detail above, those skilled in the art will readily appreciate thatmany modifications are possible in the embodiments without materiallydeparting from the novel teachings and advantages of this invention.Accordingly, all such modifications are intended to be included withinthe scope of this invention.

1. A gas heating device, comprising: one or more resistive heatingelements configured to receive an electrical current from one or morepower sources; a mounting structure configured to support said one ormore resistive heating elements; one or more static mounting devicescoupled to said mounting structure and configured to fixedly couple saidone or more resistive heating elements to said mounting structure; andone or more dynamic mounting devices coupled to said mounting structureand configured to automatically compensate for changes in a length ofeach of said one or more resistive heating elements while substantiallyreducing slippage between said one or more resistive heating elementsand said one or more dynamic mounting devices, wherein said one of saidone or more dynamic mounting devices comprises a static structure havinga guide post, a helical spring configured to slide over said guide post,and a dynamic structure configured to slidably mate with said guide postand compress said helical spring against said static structure whenloaded with said one of said one or more resistive heating elements. 2.The gas heating device of claim 1, wherein each of said one or moreresistive heating elements comprises a first end fixedly coupled to oneof said one or more static mounting devices, a second end fixedlycoupled to one of said one or more dynamic mounting devices, and astraight section extending between said first end and said second end.3. The gas heating device of claim 1, wherein each of said one or moreresistive heating elements comprises a first end fixedly coupled to oneof said one or more static mounting devices, a second end fixedlycoupled to one of said one or more static mounting devices, a bendcoupled to one of said one or more dynamic mounting devices and locatedbetween said first end and said second end, a first straight sectionextending between said first end and said bend, and a second straightsection extending between said second end and said bend.
 4. The gasheating device of claim 3, wherein said first straight section and saidsecond straight section are substantially the same length.
 5. The gasheating device of claim 4, wherein said bend comprises approximately 180degrees.
 6. The gas heating device of claim 5, wherein said one of saidone or more dynamic mounting devices is configured to adjust in a lineardirection parallel with said first straight section and said secondstraight section in order to compensate for changes in the length ofsaid first straight section and the length of said second straightsection.
 7. The gas heating device of claim 1, wherein said mountingstructure is configured to couple said gas heating device at an outletof a gas distribution system, and wherein said gas distribution systemis configured to distribute and flow a film forming composition acrossor through said one or more resistive heating elements in order causepyrolysis of one or more constituents of said film forming compositionwhen heated.
 8. The gas heating device of claim 7, wherein said gasdistribution system comprises a plenum configured to receive said filmforming composition, and one or more openings aligned with said one ormore resistive heating elements and configured to distribute and flowsaid film forming composition over said one or more resistive heatingelements.
 9. The gas heating device of claim 1, wherein said one or morepower sources comprise a direct current (DC) power source or analternating current (AC) power source.
 10. The gas heating device ofclaim 1, wherein said one or more power sources are configured to coupleelectrical power to said one or more resistive heating elements througha direct electrical connection to said one or more resistive heatingelements.
 11. The gas heating device of claim 1, wherein said one ormore power sources are configured to couple electrical power to said oneor more resistive heating elements through induction.
 12. The gasheating device of claim 1, wherein said one or more resistive heatingelements comprises a resistive metal, a resistive metal alloy, aresistive metal nitride, or a combination of two or more thereof. 13.The gas heating device of claim 1, wherein said one or more resistiveheating elements comprises a metal-containing ribbon.
 14. A processingsystem for depositing a thin film on a substrate, comprising: a processchamber having a pumping system configured to evacuate said processchamber; a substrate holder coupled to said process chamber andconfigured to support said substrate; a gas distribution system coupledto said process chamber and configured to introduce a film formingcomposition to a process space in the vicinity of a surface of saidsubstrate; and the gas heating device of claim 1 coupled to an outlet ofsaid gas distribution system.
 15. A gas heating device configured to becoupled to a processing system for depositing a thin film on asubstrate, comprising: a resistive heating element configured to receivean electrical current from a power source; a mounting structureconfigured to support said resistive heating element; a static mountingdevice coupled to said mounting structure and configured to fixedlycouple said resistive heating element to said mounting structure; and adynamic mounting device coupled to said mounting structure andconfigured to automatically compensate for changes in a length of saidresistive heating element, wherein said resistive heating elementcomprises a first end fixedly coupled to said static mounting device, asecond end fixedly coupled to said static mounting device, a bendcoupled to said dynamic mounting device and located between said firstend and said second end, a first straight section extending between saidfirst end and said bend, and a second straight section extending betweensaid second end and said bend, wherein said first straight section andsaid second straight section are substantially the same length, andwherein said dynamic mounting device comprises a static structure havinga guide post, a helical spring configured to slide over said guide post,and a dynamic structure configured to slidably mate with said guide postand compress said helical spring against said static structure whenloaded with said resistive heating element.
 16. The gas heating deviceof claim 15, wherein each of said static mounting device and saiddynamic mounting device comprises an electrically insulating material.17. The gas heating device of claim 15, wherein said power sourcecomprises a direct current (DC) power source or an alternating current(AC) power source.